Updated on 2023/02/07

写真a

 
Asada Toshio
 
Organization
Graduate School of Science Department of Chemistry Professor
School of Science Department of Chemistry
Title
Professor
Affiliation
Institute of Science
Contact information
メールアドレス
Affiliation campus
Nakamozu Campus

Position

  • Graduate School of Science Department of Chemistry 

    Professor  2022.04 - Now

  • School of Science Department of Chemistry 

    Professor  2022.04 - Now

Degree

  • Doctor (Chemistry) ( Osaka City University )

Research Areas

  • Nanotechnology/Materials / Bio chemistry  / Biochmistry

  • Nanotechnology/Materials / Functional solid state chemistry  / Functional Material Chemistry

  • Nanotechnology/Materials / Fundamental physical chemistry  / Physical Chemistry

Research Interests

  • Molecular Simulation,OLED

  • Molecular Simulation,Biomolecule,Reaction free energy profile

  • Mlolecular Orbital Method, Quantum Chemistry

  • Enzymatic reaction

  • Computational chemistry

  • Chemical reaction path on free energy surface

  • Molecular cluster

  • Carrier mobility in the amorphous phase

Research subject summary

  • 自由エネルギー面上の効率的な反応経路最適化に関する研究

  • 酵素中における基質の反応機構に関する理論的研究

  • 有機EL材料のホール輸送層シミュレーションと機械学習の活用

  • 有機EL材料を含むホスト/ゲスト複合体に関する理論的アプローチ

Research Career

  • Free Energy Analysis

    Individual

    2011.04 - Now 

  • Computational Study of Carrier Mobility in the Amorphous Phase

    Joint Research in Organization

    2011.04 - Now 

  • Theoretical study of protein

    Individual

    2000.04 - Now 

Professional Memberships

  • 理論化学会

    2019.06 - Now   Domestic

  • 分子科学会

    2006.10 - Now   Domestic

  • 日本コンピュータ化学会

    1991.04 - Now

  • 日本化学会

    1990.12 - Now

  • JAPAN SOCIETY FOR MOLECULAR SCIENCE

Education

  • Osaka City University   The second semester of doctoral program   Graduated/Completed

    1991.04 - 1994.03

  • Osaka City University     Graduated/Completed

    1989.04 - 1991.03

  • Osaka City University     Graduated/Completed

    1985.04 - 1989.03

Papers

  • Curvature-weighted nudged elastic band method using the Riemann curvature

    Mitsuta Y.

    Journal of Computational Chemistry   44 ( 5 )   662 - 669   2022( ISSN:01928651

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  • Theoretical Design of Blue-Color Phosphorescent Complexes for Organic Light Emitting Diodes: Emission Intensities and Non-Radiative Transition Rate Constants in Ir(ppy)2(acac) Derivatives Reviewed

    S.Koseki, M.Yoshii, T.Asada, Y.Fujimura, T.Matsushita, S.Yagi

    The journal of physical chemistry A   2021.12

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    Kind of work:Joint Work  

  • Climbing end image algorithm to locate transition states Reviewed

    T.Asada, N.Sawada, M.Haruta, S.Koseki

    Chemical Physics Letters 雑誌   2021.05

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    Kind of work:Joint Work  

    Repository URL: http://hdl.handle.net/10466/00017403

  • Exploring the Reaction Paths on the Potential Energy Surfaces of the S<sub>1</sub> and T<sub>1</sub> States in Methylenecyclopropane.

    Koseki S, Haruta M, Sawada N, Asada T

    Photochemistry and photobiology   97 ( 1 )   126 - 135   2021.01( ISSN:0031-8655

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  • マテリアルズインフォマティクスのためのデータ作成とその解析 Reviewed

    麻田 俊雄

    技術情報協会   2117   2021

  • Exploring the Reaction Paths on the Potential Energy Surfaces of the S1 and T1 States in Methylenecyclopropane Reviewed

    S.Koseki, M.Haruta, N.Sawada, T.Asada

    Photochemistry and Photobiology 雑誌   2020.09

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    Kind of work:Joint Work  

  • Theoretical Examination of the Plausible Reaction Process for Stereoselective Synthesis of Hexapole Helicene via a Palladium-Catalyzed [2 + 2 + 2] Cyclotrimerization of [5]Helicenyl Aryne

    Tomoka Hosokawa, Toshio Asada, Ken Kamikawa

    The Journal of Physical Chemistry A   124 ( 4 )   652 - 661   2020.01( ISSN:1089-5639

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    Publishing type:Research paper (scientific journal)  

    DOI: 10.1021/acs.jpca.9b09533

  • Theoretical Examination of Plausible Reaction Process for Stereoselective Synthesis of Hexapole Helicene via a Palladium-Catalyzed [2+2+2] Cyclotrimerization of [5]Helicenyl Aryne Reviewed

    T.Hosokawa, T.Asada, K.Kamikawa

    Journal of Physical Chemistry A 雑誌   124   652 - 661   2020.01

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    Kind of work:Joint Work  

  • Spin-Orbit Coupling Constants in Atoms and Ions of Transition Elements:Comparison of Effective Core Potentials, Model Core Potentials, and All-Electron Methods Reviewed

    S.Koseki, N.Matsunaga, T.Asada, M.Schmidt, M.Gordon

    J.Phys.Chem.A 雑誌   123   2019

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    Kind of work:Joint Work  

  • An improved reaction path optimization method using a chain of conformations Reviewed

    T.Asada, N.Sawada, T.Nishikawa, and S.Koseki

    Chem.Phys.Lett. 雑誌   Vol.699   255 - 260   2018.12

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    Kind of work:Joint Work  

  • Simulation study of hole mobility in the amorphous phase of organic molecules Reviewed

    T. Asada and S.Koseki

    Org.Elec. 雑誌   Vol.53   141 - 150   2018.12

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    Kind of work:Joint Work  

  • Computational approach for molecular design using free energy contribution analysis Reviewed

    T.Asada, B.Pradipta and S.Koseki

    AIP Proc. 雑誌   2040   2018

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    Kind of work:Joint Work  

  • Effects of the Alkyl Substituents on the Organic Thin Film Transistor Characteristics of Thiophenefused Naphthalenes: Molecular Simulation, Synthesis, and Device Characterization Reviewed

    Motoki Kumeda, Atsushi Yamamoto, Toshio Asada, Yasunori Matsui, Kenichiro Takagi, Yu Suenaga, Kunihiko Nagae, Eisuke Ohta, Takuya Ogaki, Hiroyoshi Naito, Shiro Koseki and Hiroshi Ikeda

    J. Jpn. Soc. Colour Mater. 雑誌   Vol.90   233 - 237   2017.12

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    Kind of work:Joint Work  

  • Understanding the structure and hydrogen bonding network of (H2O)32 and (H2O)33: an improved Monte Carlo Temperature Basin Paving (MCTBP) method and Quantum Theory of Atoms in Molecules (QTAIM) analysis Reviewed

    Rakshit Avijit, Takamasa Yamaguchi, Toshio Asada, Pradipta Bandyopadhyay

    RCS Advances 雑誌   Vol.7   18401 - 18417   2017.12

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    Kind of work:Joint Work  

  • Numerical Estimation of the Pseudo-Jahn-Teller Effect Using Non-Adiabatic Coupling Integrals in Monocyclic and Bicyclic Conjugated Molecules Reviewed

    Shiro Koseki, Toyota Azumao, Takashi Muramatsu, Toshio Asada, Nikita Matsunaga

    J.Phys.Chem.A 雑誌   Vol.120   10207 - 10215   2016.12

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    Kind of work:Joint Work  

  • Free Energy Contribution Analysis using Response Kernel Approximation: Insights into the Acylation Reaction for beta–lactamase Reviewed

    T.Asada, K.Ando, P.Bandyopadhyay, S.Koseki

    J.Phys.Chem.B 雑誌   Vol.120   9338 - 9346   2016.12

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    Kind of work:Joint Work  

  • Spin-Orbit Coupling Analyses of the Phosphorescence: The Effects of Cyclometalated Ligand Replacement in Ir(ppy)3 with Various bpy Ligands to Blue Phosphorescence Reviewed

    S.Koseki, S.Yagi, H.Yoshinaga, T.Asada, T.Matsushita

    RCS Advances 雑誌   Vol.6   65020 - 65030   2016.12

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    Kind of work:Joint Work  

  • Amorphous Solid Simulation and Trial Fabrication of the Organic Field-Effect Transistor of Tetrathienonaphthalenes Prepared by Using Microflow Photochemical Reactions; A Theoretical Calculation-Inspired Investigation Reviewed

    Yamamoto, Atsushi; Matsui, Yasunori; Asada, Toshio; Kumeda, Motoki; Takagi, Kenichiro; Suenaga, Yu; Nagae, Kunihiko; Ohta, Eisuke; Sato, Hiroyasu; Koseki, Shiro; Naito, Hiroyoshi; Ikeda, Hiroshi

    J.Org.Chem. 雑誌   Vol.81   3168 - 3176   2016.12

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    Kind of work:Joint Work  

  • Efficient approach to include molecular polarizations using charge and atom dipole response kernels to calculate free energy gradients in QM/MM scheme Reviewed

    T.Asada,K.Ando,K.Sakurai,S.Koseki,M.Nagaoka

    Phys.Chem.Chem.Phys. 雑誌   Vol.17   2015.12

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    Kind of work:Joint Work  

  • Spin-Orbit Coupling Analyses on Phosphorescent Processes in Ir(Zppy)3 (Z = NH2, NO2 and CN) Reviewed

    H.Yoshinaga,T.Asada,S.Koseki

    RSC Adv. 雑誌   Vol.5   35760 - 35772   2015.12

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    Kind of work:Joint Work  

  • Efficient approach to obtain free energy gradient using QM/MM MD simulation Reviewed

    T.Asada,K.Ando,S.Koseki

    AIP Conf. Proc. 雑誌   Vol. 1702   2015.12

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    Kind of work:Joint Work  

  • Synthesis of Double Helicene by Palladium Catalyzed Cross-Coupling Reaction: Structure and Physical Properties Reviewed

    H.Kashiwara, ; T.Asada; K.Kamikawa

    Chem.Eur.J. 雑誌   Vol.21   1 - 6   2015.12

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  • Efficient approach to include molecular polarizations using charge and atom dipole response kernels to calculate free energy gradients in the QM/MM scheme Reviewed

    Toshio Asada, Kanta Ando, Koji Sakurai, Shiro Koseki, Masataka Nagaoka

    PHYSICAL CHEMISTRY CHEMICAL PHYSICS   17 ( 40 )   26955 - 26968   2015( ISSN:1463-9076

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    An efficient approach to evaluate free energy gradients (FEGs) within the quantum mechanical/molecular mechanical (QM/MM) framework has been proposed to clarify reaction processes on the free energy surface (FES) in molecular assemblies. The method is based on response kernel approximations denoted as the charge and the atom dipole response kernel (CDRK) model that include explicitly induced atom dipoles. The CDRK model was able to reproduce polarization effects for both electrostatic interactions between QM and MM regions and internal energies in the QM region obtained by conventional QM/MM methods. In contrast to charge response kernel (CRK) models, CDRK models could be applied to various kinds of molecules, even linear or planer molecules, without using imaginary interaction sites. Use of the CDRK model enabled us to obtain FEGs on QM atoms in significantly reduced computational time. It was also clearly demonstrated that the time development of QM forces of the solvated propylene carbonate radical cation (PC center dot+) provided reliable results for 1 ns molecular dynamics (MD) simulation, which were quantitatively in good agreement with expensive QM/MM results. Using FEG and nudged elastic band (NEB) methods, we found two optimized reaction paths on the FES for decomposition reactions to generate CO2 molecules from PC center dot+, whose reaction is known as one of the degradation mechanisms in the lithium-ion battery. Two of these reactions proceed through an identical intermediate structure whose molecular dipole moment is larger than that of the reactant to be stabilized in the solvent, which has a high relative dielectric constant. Thus, in order to prevent decomposition reactions, PC center dot+ should be modified to have a smaller dipole moment along two reaction paths.

    DOI: 10.1039/c5cp04423e

    PubMed

  • Theoretical analyses on phosphorescent processes in Pt(thpy)2 and its derivatives Reviewed

    S.Koseki, Y.Kagita, S.Matsumoto, T.Asada, S.Yagi, H.Nakazumi

    J.Phys.Chem.C 雑誌   Vol.118   2014.12

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  • Theoretical Analyses on Phosphorescent Processes in Pt(thpy)(2) and Its Derivatives Reviewed

    Shiro Koseki, Yuhld Kagita, Sachiko Matsumoto, Toshio Asada, Shigayuki Yagi, Hiroyuki Nakazumi, Takeshi Matsushita

    JOURNAL OF PHYSICAL CHEMISTRY C   118 ( 28 )   15412 - 15421   2014.07( ISSN:1932-7447

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    Theoretical estimation of the peak wavelengths of phosphorescence was performed at the MCSCF+SOCI/SBKJC+p level of theory for several typical platinum complexes in the research field of organic-light-emitting-diodes (OLEDs), where MCSCF +SOCI is the abbreviation of multiconfiguration self-consistent field calculations followed by second-order configuration interaction calculations. The spin orbit coupling (SOC) integrals among low-lying electronic states of different spin multiplicities were explicitly calculated within the Z(eff) approximation. By using these computational methods, the experimental results for peak wavelengths of phosphorescence were reasonably explained for cis-bis[2-(2'-thienyl)pyridinato-N,C-3']platinum(II) and its derivatives. The replacement of one of the 2-(2'-thienyl)pyridinate (thpy) ligands by a 2,4-pentanedionate (acac) ligand causes a blue shift of the phosphorescent peak by about 10 nm. The use of a 1,3-bis(phenyl)propane-1,3-dionate (bpp), 1,3-bis(n-methoxyphenyl)propane-1,3-dionate (bmp), or 1,3-bis(3,4-methoxyphenyl)propane-1,3-dionate (bdmp) ligand, instead of an acac ligand, has almost no effect on the peak wavelength of phosphorescence. When a benzene ring is fused to a thpy ligand, the peak wavelength is estimated to be 613 or 651 nm for [2,2'-(4',5'-benzo)thienyl)pyridinato-N,C-3'][1,3-bis(3,4-dibutoxyphenyl)-propane-1,3-dionato-O,O]platinum(II) [btpPt(bdbp)] and [1-(2'-thienyl)isoquinolyl-N,C-3'] [1,3-bis(3,4-dibutoxyphenyl)-propane-1,3-dionato-O,O]platinum(II) [1tiqPt(bdbp)], respectively, after correction of the present computational underestimation. These theoretical estimations are in good agreement with the corresponding observations.

    DOI: 10.1021/jp5046832

  • Spin-Orbit Coupling Analyses of the Geometrical Effects on Phosphorescence in Ir(ppy)3 and Its Derivatives Reviewed

    .Koseki, N.Kamata, T.Asada, S.Yagi, H.Nakazumi, T.Matsushita

    J.Phys.Chem.C 雑誌   Vol.117   2013.12

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  • Theoretical Investigation of the Reaction Mechanism of ClONO2 + HCl → HNO3 + Cl2 on (H2O)n (n = 0-3) Cluster Reviewed

    T.Asada, T.Okajima, S.Koseki

    J.Phys.Chem.A 雑誌   Vol.117   7928 - 7938   2013.12

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  • Theoretical Investigation of the Reaction Mechanism of ClONO2 + HCl -&gt; HNO3 + Cl-2 on (H2O)(n) (n=0-3) Cluster Reviewed

    Toshio Asada, Toshiyuki Okajima, Shiro Koseki

    JOURNAL OF PHYSICAL CHEMISTRY A   117 ( 33 )   7928 - 7938   2013.08( ISSN:1089-5639

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    Hydrated chlorine nitrate and hydrogen chloride ClONO2 center dot HCl center dot(H2O)(n) (n = 0-3) clusters were investigated by using the MP2/aug-cc-pVTZ level of theory to clarify the reaction mechanism of Cl-2 production. Isomeric stable structures found in n = 2 and 3 clusters have equivalent binding energies and the reaction barrier drastically decreases to be 2.1 kcal/mol at n = 3. The plausible reaction pathways were proposed according to calculated structures and energies, where the zero-point-energy corrections are important to determine the energy profiles of reactions especially for the n = 3 cluster. The kinetic analysis using the transition state theory suggested that the reaction rate constant from the original reactants to the product of n = 3 is 1.8 x 10(5) times larger than that of n = 2 cluster. Even though the small amount of the molar concentration of HCl(H2O)(3) is obtained, the overall reaction rate of the trihydrate reaction is still 35 times faster than that of the dihydrate.

    DOI: 10.1021/jp406175j

    PubMed

  • Spin-Orbit Coupling Analyses of the Geometrical Effects on Phosphorescence in Ir(ppy)(3) and Its Derivatives Reviewed

    Shiro Koseki, Na-oya Kamata, Toshio Asada, Shigeyuki Yagi, Hiroyuki Nakazumi, Takeshi Matsushita

    JOURNAL OF PHYSICAL CHEMISTRY C   117 ( 10 )   5314 - 5327   2013.03( ISSN:1932-7447

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    Theoretical investigations were performed for typical iridium complexes, Ir((CN)-N-boolean AND)(3), Ir((CN)-N-boolean AND)(2)(C'N-boolean AND'), Ir-((CN)-N-boolean AND)(2)((NO)-O-boolean AND) and Ir((CN)-N-boolean AND)(2)((OO)-O-boolean AND), at the MCSCF+SOCI+SOC//B3LYP/SBKJC+p level of theory. For Ir(dfppy)(2)(pic) (so-called FIrpic) and its related complexes, the introduction of a fluoride into ppy ligands provides a blue shift of about 20 nm for emission spectra, while the replacement of a pic ligand by an acac ligand does not seriously affect the emission spectra of these complexes. It is proposed that the homo-cis,hetero-O-cis isomer (HC-5f, see text) of FIrpic should be used as a brighter blue-color material instead of the homo-N-trans isomer (HNT-5f). The energy difference between these isomers is less than 1 kcal/mol, and the energy barrier of the isomerization between these isomers is calculated to be larger than 30 kcal/mol. It was also found that the use of two ancillary ligands, such as Ir((CN)-N-boolean AND)((NO)-O-boolean AND)(2) and Ir((CN)-N-boolean AND)((OO)-O-boolean AND)(2), is unfortunately inappropriate to energetically lift the pi* orbital.

    DOI: 10.1021/jp312032s

  • Toward a new approach for determination of solute's charge distribution to analyze interatomic electrostatic interactions in quantum mechanical/molecular mechanical simulations.

    Yamada K, Koyano Y, Okamoto T, Asada T, Koga N, Nagaoka M

    Journal of computational chemistry   32 ( 14 )   3092 - 104   2011.11( ISSN:0192-8651

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  • A minimal implementation of the AMBER-GAUSSIAN interface for ab initio QM/MM-MD simulation.

    Okamoto T, Yamada K, Koyano Y, Asada T, Koga N, Nagaoka M

    Journal of computational chemistry   32 ( 5 )   932 - 42   2011.04( ISSN:0192-8651

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  • QM/MM investigation on the degradation mechanism of the electron transporting layer Reviewed

    T.Asada, K.Ohta, S.Koseki

    Theo.Chem.Acc.   130   439 - 448   2011

  • Reaction path optimization and vibrational frequency analysis via ab initio QM/MM free energy gradient (FEG) method: application to isomerization process of glycine in aqueous solution Reviewed

    N.Takenaka, Y.Koyano, Y.Kitamura, T.Asada, M.Nagaoka

    Theo.Chem.Acc.   130   215 - 226   2011

  • Toward a new approach for determination of solute's charge distribution to analyze interatomic electrostatic interaction in quantum mechanical/molecular mechanical simulations Reviewed

    K.Yamada, Y.Koyano, T.Okamoto, T.Asada, N.Koga, M.Nagaoka

    J.Comp.Chem. 雑誌   32   3092 - 3104   2011

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    Kind of work:Joint Work  

  • A Minimal Implementation of the AMBER-GAUSSIAN Interface for Ab Initio QM/MM-MD Simulation Reviewed

    T.Okamoto, K.Yamada, Y.Koyano, T.Asada, N.Koga, M.Nagaoka

    J.Comp.Chem. 雑誌   32   932 - 942   2011

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  • Ab initio electron correlation studies of the intracluster reaction NO+(H2O)N --> H3O+(H2O)n-2(HONO) at n=4 and 5 Reviewed

    T.Asada, S.Koseki, M.Nagaoka

    Phys.Chem.Chem.Phys. 雑誌   13   1590 - 1596   2011

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  • Ab initio electron correlated studies on the intracluster reaction of NO+(H2O)(n) -&gt; H3O+(H2O)(n-2) (HONO) (n=4 and 5) Reviewed

    Toshio Asada, Masataka Nagaoka, Shiro Koseki

    PHYSICAL CHEMISTRY CHEMICAL PHYSICS   13 ( 4 )   1590 - 1596   2011( ISSN:1463-9076

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    Hydrated nitrosonium ion clusters NO+(H2O)(n) (n = 4 and 5) were investigated by using MP2/aug-cc-pVTZ level of theory to clarify isomeric reaction pathways for formation of HONO and fully hydrated hydride ions. We found some new isomers and transition state structures in each hydration number, whose lowest activation energies of the intracluster reactions were found to be 4.1 and 3.4 kcal mol(-1) for n = 4 and n = 5, respectively. These thermodynamic properties and full quantum mechanical molecular dynamics simulation suggest that product isomers with HONO and fully hydrated hydride ions can be obtained at n = 4 and n = 5 in terms of excess hydration binding energies which can overcome these activation barriers.

    DOI: 10.1039/c0cp01077d

    PubMed

  • Tetrahydrides of third-row transition elements: Spin-orbit coupling effects on the stability of rhenium tetrahydride Reviewed

    Shiro Koseki, Taka-aki Hisashima, Toshio Asada, Azumao Toyota, Nikita Matsunaga

    JOURNAL OF CHEMICAL PHYSICS   133 ( 17 )   174112   2010.11( ISSN:0021-9606

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    The potential energy surfaces of low-lying states in rhenium tetrahydride (ReH4) were explored by using the multiconfiguration self-consistent field (MCSCF) method together with the SBKJC effective core potentials and the associated basis sets augmented by a set of f functions on rhenium atom and by a set of p functions on hydrogen atoms, followed by spin-orbit coupling (SOC) calculations to incorporate nonscalar relativistic effects. The most stable structure of ReH4 was found to have a D-2d symmetry and its ground state is (4)A(2). It is found that this is lower in energy than the dissociation limit, ReH2 + H-2, after dynamic correlation effects are taken into account by using second-order multireference Moller-Plesset perturbation (MRMP2) calculations. This reasonably agrees with previous results reported by Andrews et al. [J. Phys. Chem. 107, 4081 (2003)]. The present investigation further revealed that the dissociation reaction of ReH4 cannot occur without electronic transition from the lowest quartet state to the lowest sextet state. This spin-forbidden transition can easily occur because of large SOC effects among low-lying states in such heavy metal-containing compounds. The minimum-energy crossing (MEX) point between the lowest quartet and sextet states is proved to be energetically and geometrically close to the transition state for the dissociation reaction on the potential energy surface of the lowest spin-mixed state. The MEX point (C-2 symmetry) was estimated to be 9184 cm(-1) (26.3 kcal/mol) higher than the (4)A(2) state in D-2d symmetry at the MRMP2 level of theory. After inclusion of SOC effects, an energy maximum on the lowest spin-mixed state appears near the MEX point and is recognized as the transition state for the dissociation reaction to ReH2 + H-2. The energy barrier for the dissociation, evaluated to be MEX in the adiabatic picture, was calculated to be 5643 cm(-1) (16.1 kcal/mol) on the lowest spin-mixed state when SOC effects were estimated at the MCSCF level of theory. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3495680]

    DOI: 10.1063/1.3495680

    PubMed

  • Tetra-hydrides of Third-Row Transition Elements: Spin-Orbit Coupling Effects on the Stability of Rhenium Tetra-hydrides Reviewed

    S.Koseki, H.Hisashima, T.Asada, A.Toyota, N.Matsunaga

    J.Chem.Phys. 雑誌   133   174112 - 174120   2010

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  • Theoretical Study on the Absorption Spectra of fac-Ir(ppy)3 in the Amorphous Phase of Organic Electro-Luminescent Devices Reviewed

    T.Asada, S.Hamamura, T.Matsushita, and S.Koseki

    Res.Chem.Int. 雑誌   35   851 - 863   2009.10

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  • Spin-orbit coupling effects in dihydrides of third-row transition elements. II. Interplay of nonadiabatic coupling in the dissociation path of rhenium dihydride.

    Koseki S, Shimakura N, Fujimura Y, Asada T, Kono H

    The Journal of chemical physics   131 ( 4 )   044122   2009.07( ISSN:0021-9606

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  • Spin-orbit coupling effects in dihydrides of third-row transition elements. II. Interplay of nonadiabatic coupling in the dissociation path of rhenium dihydride Reviewed

    S.Koseki, N.Shimakura, Y.Fujimura, T.Asada, and H.Kono

    J.Chem.Phys. 雑誌   131   44122 - 44129   2009.07

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  • Theoretical Study on Phosphorescent Materials for Organic Electro-Luminescent Devices Reviewed

    S.Koseki, T.Asada, and T.Matsushita

    J.Comp.Theo.Nanoscience 雑誌   6   1352 - 1360   2009.07

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  • Simulation Study of Interactions and Reactivities between NADH Cytochrom b5 Reductase and Cytochrome b5 Reviewed

    T.Asada, S.Nagase, K.Nishimoto, and S.Koseki

    J.Mol.Liq. 雑誌   147   139 - 144   2009.03

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  • Molecular dynamics simulation study on stabilities and reactivities of NADH cytochrom b5 reductase Reviewed

    T.Asada, S.Nagase, K.Nishimoto, and S.Koseki

    J.Phys.Chem.B 雑誌   112   5718 - 5727   2008.05

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  • Molecular dynamics simulation study on stabilities and reactivities of NADH cytochrome B5 reductase Reviewed

    Toshio Asada, Shigeru Nagase, Kichisuke Nishimoto, Shiro Koseki

    JOURNAL OF PHYSICAL CHEMISTRY B   112 ( 18 )   5718 - 5727   2008.05( ISSN:1520-6106

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    Binding free energies between coenzyme (FAD and NADH) and the apoenzyme of NADH-cytochrome b5 reductase (b5R) were estimated by applying the continuum Poisson-Boltzmann (PB) model to structures sampled from molecular dynamics simulations in explicit water molecules. Important residues for the enzymatic catalysis were clarified using a computational alanine scanning method. The binding free energies calculated by applying an alanine scanning method can successfully reproduce the trends of the measured steady-state enzymatic activities k(cat)(NADH)/K(m)(NADH). Significant decreases in the binding free energy are expected when one of the four residues Arg91, Lysl 10, Ser127, and Thr181 is mutated into Ala. According to the results of the molecular dynamics simulation, Thr181 is considered to be one of the key residues that helps NADH to approach the isoalloxazine in FAD. Finally, we have constructed very simplified model systems and carried out density functional theory calculations using B3LYP/LANL2DZ//ROHF(or RHF)/LANL2DZ level of theory in order to elucidate a realistic and feasible mechanism of the hydride-ion transfer from NADH to FAD affected by HEME(Fe(3+)) as an electron acceptor. Our calculated results suggest that the electron and/or hydrideion transfer reaction from NADH to FAD can be accelerated in the presence of HEME(Fe(3+)).

    DOI: 10.1021/jp7101513

    PubMed

  • Relativistic study on emission mechanism in tris(2-phenylpyridine)iridium Reviewed

    Takeshi Matsushita, Toshio Asada, Shiro Koseki

    JOURNAL OF PHYSICAL CHEMISTRY C   111 ( 18 )   6897 - 6903   2007.05( ISSN:1932-7447

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    Publishing type:Research paper (scientific journal)  

    The mechanisms of radiative processes from electronically excited states were investigated for tris(2-phenylpyridine)iridium [Ir(ppy)(3)]. It was found that low-lying excited singlet and triplet states in the facial (fac) isomer are strongly mixed with each other by spin-orbit coupling (SOC) effects and, as a result, the radiative transitions could occur easily from low-lying spin-mixed states to the lowest spin-mixed state (ground state), where the low-lying spin-mixed states mainly have a triplet character. On the basis of the assumption that radiative processes obey Fermi&apos;s Golden rule, large transition probabilities are obtained between the sublevels of the adiabatic lowest triplet state (T(1)) and the ground state (S(0)), and phosphorescence is expected to be observed in this complex. This result is in good agreement with experimental reports.

    DOI: 10.1021/jp0708796

  • Relativistic Study on Emission Mechanism in tris-(2-Phenylpyridine) Iridium Reviewed

    T.Matsushita, T.Asada, and S.Koseki

    J.Phys.Chem.C 雑誌   111   6897 - 6903   2007.04

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    Kind of work:Joint Work  

  • Tetra-Hydrides of the Third-Row Transition Elements: Spin-Orbit Coupling Effects on Geometrical Deformation in WH4 and OsH4 Reviewed

    T.Hisashima, T.Matsushita, T.Asada, and S.Koseki

    Theo.Chem.Acc. 雑誌   120   85 - 94   2007.04

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    Kind of work:Joint Work  

  • Theoretical study of environmental effects for proton transfer reaction through the peptide bond in a model system Reviewed

    T.Asada, T.Takahashi, S.Koseki

    Theo.Chem.Acc. 雑誌   120   263 - 271   2007.04

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  • Relativistic study on emission mechanism in palladium and platinum complexes Reviewed

    Takeshi Matsushita, Toshio Asada, Shiro Koseki

    JOURNAL OF PHYSICAL CHEMISTRY A   110 ( 49 )   13295 - 13302   2006.12( ISSN:1089-5639

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    Publishing type:Research paper (scientific journal)  

    The present study investigates the spin-orbit coupling (SOC) effects in the radiative processes from the electronically excited states of bis-[2-(2-thienyl)-pyridine] platinum (Pt(thpy)(2)) and palladium (Pd( thpy) 2). The transition probabilities among the low-lying spin-mixed states in these complexes are estimated using the discrete variable representation (DVR) method based on the assumption that the system obeys Fermi&apos;s golden rule. It is revealed that the low-lying excited singlets and triplets are strongly mixed with each other by SOC in Pt(thpy) 2 and, as a result, a fast nonradiative transition occurs to the low-lying excited spin-mixed states. This is followed by the radiative transition from these low-lying spin-mixed states to the lowest spin-mixed state (the ground state); that is to say, a phosphorescence should be observed from these low-lying excited spin-mixed states in Pt(thpy)(2). On the contrary, weak SOCs are obtained in Pd(thpy)(2) and no phosphorescence at room temperature is expected to be observed in Pd(thpy)(2). These results are in good agreement with the experimental reports.

    DOI: 10.1021/jp0632992

    PubMed

  • Relativistic Study on Emission Mechanism in Paraddium and Platunum Complexes Reviewed

    T.Matsushita, T.Asada, and S.Koseki

    J.Phys.Chem.A 雑誌   110   13295 - 13302   2006.09

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  • Theoretical Calculation of Structures and Proton Transfer in Hydrated Ammonia Hydrogen Chloride Clusters Reviewed

    Toshio Asada, Seisuke Takitani, Shiro Koseki

    The Journal of Physical Chemistry A 雑誌   109   1821 - 1827   2005.04

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  • Theoretical calculation of structures and proton transfer in hydrated ammonia-hydrogen chloride clusters Reviewed

    Toshio Asada, Seisuke Takitani, Shiro Koseki

    Journal of Physical Chemistry A   109 ( 9 )   1821 - 1827   2005.03( ISSN:1089-5639

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    Publishing type:Research paper (scientific journal)  

    Ab initio molecular orbital calculations have been performed to investigate the structures and quantum effects of the proton motion in NH 3:HCl:(H220)n (n = 0-3) clusters using a MP2/aug-cc-pVDZ level of theory. Three new stable structures and one transition-state structure are investigated for these clusters. The detailed analyses of the intermolecular interactions suggest that three-body interactions play an important role to determine the relative stability in each size of cluster. The quantum effects of the proton motion result in frequency shifts for proton-stretching modes. Our one-dimensional and two-dimensional models fairly closely reproduce the experimental proton-stretching vibrational frequency of the NH3:HCl cluster. The most stable isomer for n = 1 has a proton-transfer structure, which is weakened by the quantum effects of the proton motion. © 2005 American Chemical Society.

    DOI: 10.1021/jp045933m

    PubMed

  • Molecular dynamics simulation study of the negative correlation in antibody AZ28-catalyzed oxy-cope rearrangement.

    Asada T, Gouda H, Kollman PA

    Journal of the American Chemical Society   124 ( 42 )   12535 - 42   2002.10( ISSN:0002-7863

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  • Molecular dynamics simulation study of the negative correlation in antibody AZ28 catalyzed oxy-Cope rearrangement Reviewed

    Toshio Asada, Hiroaki Gouda, Peter A. Kollman

    Journal of the American Chemical Society 雑誌   124   12535 - 12542   2002.08

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    Kind of work:Joint Work  

  • Simulation study of proton transfer for N2H7+ cluster by classical ab initio and quantum wave packet dynamics Reviewed

    Toshio Asada, Haruya Haraguchi, Kazuo Kitaura

    The Journal of Physical Chemistry A 雑誌   105   7423 - 7428   2001.07

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    Kind of work:Joint Work  

  • Vibrational assignments of lithium alkyl carbonate and lithium alkoxide in the infrared spectra: an ab initio MO study Reviewed

    S.Matsuta, T.Asada, K.Kitaura

    J.Electrochem.Soc. 雑誌   Vol.147 ( 5 )   1695 - 1702   2000.12

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    Kind of work:Joint Work  

  • Fragment Molecular Orbital Method: An ApproximateComputational Method for Large Molecule Reviewed

    K.Kitaura, E.Ikeo,T.Asada, T.Nakano, and M.Uebayashi

    Chem.Phys.Lett. 雑誌   Vol.313   701 - 706   1999.12

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    Kind of work:Joint Work  

  • Pair interaction molecular orbital method: an approximatecomputational method for molecular interactions Reviewed

    K.Kitaura, T.Sawai, T.Asada, T.Nakano, M.Uebayashi

    Chem.Phys.Lett. 雑誌   Vol.312   319 - 324   1999.12

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    Kind of work:Joint Work  

  • Ab Initio MO Study of the Flavin Catalyzed DehydrogenationReaction of Glycine - PTC driving Hydride Transfer Mechanism Reviewed

    K.Nishimoto,K.Higashimura, T.Asada

    Theo.Chem.Acc. 雑誌 Springer-Verlag   Vol.102   355 - 365   1999.12

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    Kind of work:Joint Work  

  • Structures of Cl-CH3Cl(H2O)n (n=0,1,2) cluster at roomtemperature from Monte Carlo samplings using the ab initio MO method Reviewed

    T.Asada, N.Kato, K.Kitaura

    J.Mol.Struct.(Theochem). 雑誌 Elsevier   Vol.461-462   493 - 502   1999.12

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    Kind of work:Joint Work  

  • Hybrid Procedure of Ab Initio Molecular Orbital (MO) andMonte Carlo Samplings; Application to Cluster B+(H2O) Reviewed

    H.Watanabe, T.Asada

    Chem.Phys. 雑誌 Elsevier   Vol.237   81 - 90   1998.12

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    Kind of work:Joint Work  

  • Theoretical Prediction of Intracluster Reactions of B+(H2O)2and B+(H2O)3: Hybrid Procedure of Ab Initio MO Calculations and Monte Calro Samplings. Reviewed

    H.Watanabe, T.Asada, S.Iwata

    Bull.Chem.Soc.Jpn. 雑誌   Vol.70 ( 11 )   2619 - 2629   1997.12

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    Kind of work:Joint Work  

  • Hybrid procedure of ab initio molecular orbital calculation and Monte Carlo simulation for studying the intracluster reactions: Applications to Mg+(H2O)n (n=1~4) Reviewed

    T.Asada, S.Iwata

    Chem.Phys.Lett. 雑誌   Vol.260   1996.12

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    Kind of work:Joint Work  

  • Structural Features for Hydrated CN- Clusters at Room Temperature Reviewed

    T.Ikeda,K.Nishimoto, T.Asada

    Chem.Phys.Lett. 雑誌 Elsevier   Vol.248   329 - 335   1996.12

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    Kind of work:Joint Work  

  • Monte Carlo Simulations of M+Cl-(H2O)n (M=Li,Na) Clusters- Structure, Fluctuations, and Possible Dissolving Mechanism Reviewed

    T.Asada, K.Nishimoto

    Mol.Simul. 雑誌 Overseas Publishers Association   Vol.16 ( 16 )   309 - 319   1996.12

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    Kind of work:Joint Work  

  • Monte Carlo Simulations of M+Cl-(H2O)n (M=Li,Na) Clustersand the Dissolving Mechanism of Ion Pairs in Water Reviewed

    T.Asada, K.Nishimoto

    Chem.Phys.Lett. 雑誌   Vol.232   518 - 523   1995.12

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    Kind of work:Joint Work  

  • Melting Phenomena of Cl-(H2O)2 Clusters Reviewed

    T.Asada, K.Nishimoto, K.Kitaura

    J.Mol.Struct.(Theochem). 雑誌 Elsevier   Vol.310   149 - 153   1994.12

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    Kind of work:Joint Work  

  • Theoretical Study on Binding Enthalpies and Pupulations ofIsomers of Cl-(H2O)n Clusters at Room Temperature Reviewed

    T.Asada, K.Nishimoto, K.Kitaura

    J.Phys.Chem. 雑誌   Vol.90 ( 29 )   7724 - 7729   1993.12

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    Kind of work:Joint Work  

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Books and Other Publications

  • マテリアルズインフォマティクスのための データ作成とその解析、応用事例

    船津 公人, 麻田 俊雄 他( Role: Joint author)

    技術情報協会  2021.07  ( ISBN:978-4-86104-85

MISC

  • Understanding the structure and hydrogen bonding network of (H2O)(32) and (H2O)(33): an improved Monte Carlo temperature basin paving (MCTBP) method and quantum theory of atoms in molecules (QTAIM) analysis

    Avijit Rakshit, Takamasa Yamaguchi, Toshio Asada, Pradipta Bandyopadhyay

    RSC ADVANCES   7 ( 30 )   18401 - 18417   2017( ISSN:2046-2069

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    Large water clusters are of particular interest because of their connection to liquid water and the intricate hydrogen bonding networks they possess. Generally, clusters above (H2O)(25) are cage-like; however, the diversity of their hydrogen bonding can be enormous and is related to the stability of the cluster. Two main challenges for understanding hydrogen bonding networks are how to determine a few low energy minima in the extremely rugged energy surface of large water clusters and how to rationalize the relative stability of different structures of a cluster based on simple chemical concepts, particularly when they are very close in energy. In the current work, an improved version of the Monte Carlo Temperature Basin Paving (MCTBP) method has been used to find low energy structures of (H2O)(32) and (H2O)(33) as an answer to the first challenge. Previously, the MCTBP method has been applied to large water clusters with reasonable success. In this work, we have changed the Monte Carlo acceptance/rejection condition to make the calculation more efficient. After finding several structures at either the same or lower energy of previously known structures, the quantum theory of atoms in molecules (QTAIM) method has been applied to analyze the relationship between the stability and polarized charges on each water molecule in a cluster. Overall, an increase of the polarized charge on the oxygen atom was found to stabilize the energy of a water molecule in a cluster.

    DOI: 10.1039/c6ra28688g

  • Spin-orbit coupling analyses of phosphorescence: the effects of cyclometalated ligand replacement in fac-Ir(ppy)(3) with various bpy ligands on blue phosphorescence

    Harunobu Yoshinaga, Toshio Asada, Shiro Koseki, Shigeyuki Yagi, Takeshi Matsushita

    RSC ADVANCES   6 ( 69 )   65020 - 65030   2016( ISSN:2046-2069

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    Multi-configuration self-consistent field (MCSCF) calculations followed by second-order configuration interaction (SOCI) and spin-orbit coupling (SOC) calculations were performed using one of the effective core potentials and its associated basis set, the Stevens-Basch-Krauss-Jasien-Cundari (SBKJC) basis set referred to here as SBKJC+p, in order to examine the effects of replacement of a methine group in each phenylpyridine (ppy) ligand of the facial (fac) isomer of tris(2-phenylpyridinato)iridium(III)[fac-Ir(ppy)(3)] by a nitrogen atom for the purpose of obtaining deep blue phosphorescence. Only replacements of the methine group at the 3' or 5' site of each ppy ligand by nitrogen atoms were calculated to induce a spectral shift to the blue region. These results can be explained by the strong electronegativity of nitrogen atoms and by the magnitude of the electron density at the 2' carbon atom of the ppy or bipyridine (bpy) ligands. Subsequently, the substituent effects in the fac isomer of tris(bipyridinato)iridium(III)[fac-Ir(bpy)(3)] were investigated and found to be similar to those in fac-Ir(ppy)(3) as reported in our previous study (RSC Adv., 2015, 5, 35760-35772). Based on systematic calculations and theoretical consideration, the most effective modification for deep blue phosphorescence should be the introduction of a nitrogen atom into the 3' or/and 5' site of benzene rings of the ppy ligands in fac-Ir(ppy)(3) together with the combination of the substituents X = F, NR2, or OR (R = alkyl group) and Y = CN or NO2.

    DOI: 10.1039/c6ra07778a

  • Efficient Approach to Obtain Free Energy Gradient using QM/MM MD Simulation

    Toshio Asada, Kanta Ando, Shiro Koseki

    INTERNATIONAL CONFERENCE OF COMPUTATIONAL METHODS IN SCIENCES AND ENGINEERING 2015 (ICCMSE 2015)   1702   2015( ISSN:0094-243X

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    The efficient computational approach denoted as charge and atom dipole response kernel (CDRK) model to consider polarization effects of the quantum mechanical (QM) region is described using the charge response and the atom dipole response kernels for free energy gradient (FEG) calculations in the quantum mechanical/molecular mechanical (QM/MM) method. CDRK model can reasonably reproduce energies and also energy gradients of QM and MM atoms obtained by expensive QM/MM calculations in a drastically reduced computational time. This model is applied on the acylation reaction in hydrated trypsin-BPTI complex to optimize the reaction path on the free energy surface by means of FEG and the nudged elastic band (NEB) method.

    DOI: 10.1063/1.4938813

  • Spin-orbit coupling analyses of phosphorescent processes in Ir(Zppy)(3) (Z = NH2, NO2 and CN)

    Shiro Koseki, Harunobu Yoshinaga, Toshio Asada, Takeshi Matsushita

    RSC ADVANCES   5 ( 45 )   35760 - 35772   2015( ISSN:2046-2069

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    Substituent effects of NH2, NO2 and CN groups on phosphorescence in fac-tris(2- phenylpyridinato)-iridium(III) [fac-Ir(ppy)(3)] were examined theoretically by using the multiconfiguration self-consistent field (MCSCF) method together with the SBKJC basis sets augmented by a set of polarization functions, followed by second-order configuration interaction (SOCI) and spin-orbit coupling (SOC) calculations, while time-dependent density functional theory (TD DFT) calculations provided too long wavelengths for phosphorescent peaks at the geometries optimized for triplet states even though the TD DFT predictions were qualitatively good with respect to relative spectral shifts. The strongest electron-donating substituent NH2 and the strongest electron-withdrawing substituents, NO2 and CN, were chosen for investigation of the substituent effects in the present investigation. It was found that when these electron-withdrawing substituents are introduced into the Z(5) sites, the largest blue shift is obtained for the emission spectra, while the introduction of the electron-donating NH2 substituent causes a red shift of the emission spectra. This is because the Z(5) site has non-negligible coefficients in the highest occupied molecular orbital (HOMO) and can interact with the pi* orbitals of the substituents. This interaction makes the HOMO lower in energy. This is the reason why a large blue shift of the emission peak is obtained when one of these substituents is introduced to the Z(5) sites. Based on the results of the calculation, it can be said that the best material for blue-color emission is tris(5-nitro-2-phenylpyridinato) iridium(III) [fac-Ir(5-NO2-ppy)(3)] or tris(5-nitro-4,6-difluoro-2-phenylpyridinato) iridium(III) [fac-Ir(5-NO2-4,6-dfppy)(3)]. If the reactivity of the NO2 substituent in the lowest triplet state becomes troublesome in the synthesis processes and/or if it is difficult to choose host molecules for an emissive layer, tris(5-cyano-3,4,6-trifluoro-2-phenylpyridinato) iridium(III) [fac-Ir(5-CN-3,4,6-tfppy)(3)] would be the most appropriate for blue-color emission.

    DOI: 10.1039/c5ra04487a

  • Molecular dynamics simulation study of the negative correlation in antibody AZ28-catalyzed oxy-Cope rearrangement

    T Asada, H Gouda, PA Kollman

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   124 ( 42 )   12535 - 12542   2002.10( ISSN:0002-7863

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    The oxy-Cope rearrangement reaction in the antibody AZ28 is investigated using ab initio molecular orbital calculations and molecular mechanical molecular dynamics simulations. This antibody, AZ28, is known as one of the few systems where the mature catalytic antibody shows a negative correlation between the transition state analogue (TSA) binding affinity and the catalytic rate of the oxy-Cope rearrangement compared to the germ line catalytic antibody. The ab initio optimized structure shows that the transition state structure has a more planar configuration than the TSA. The favorable electrostatic interactions between AZ28 and the transition state analogue overcome the unfavorable van der Waals interactions; thus, AZ28 shows higher binding affinity for the TSA than the germ line. However, the AZ28 is not flexible enough to accept the relatively planar transition state structure. Because the lower flexibility causes poorer antibody-hapten interaction energies, the activation free energy of the oxy-Cope rearrangement becomes larger in the mature antibody than the germ line. We show that the differences in flexibility between the germ line and the mature form and the differences in structure between TSA and the transition state are the origin of the negative correlation in AZ28-catalyzed oxy-Cope rearrangement. The mutation of residue 34 of the light chain, 34(L), affects the binding free energies through the interresidue interaction because it is the closest to the hapten among the six mutatable residues. However, it does not affect the negative correlation.

    DOI: 10.1021/ja020774a

    PubMed

    CiNii Article

  • Molecular dynamics simulation study of the negative correlation in antibody AZ28-catalyzed oxy-Cope rearrangement

    T Asada, H Gouda, PA Kollman

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   124 ( 42 )   12535 - 12542   2002.10( ISSN:0002-7863

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    The oxy-Cope rearrangement reaction in the antibody AZ28 is investigated using ab initio molecular orbital calculations and molecular mechanical molecular dynamics simulations. This antibody, AZ28, is known as one of the few systems where the mature catalytic antibody shows a negative correlation between the transition state analogue (TSA) binding affinity and the catalytic rate of the oxy-Cope rearrangement compared to the germ line catalytic antibody. The ab initio optimized structure shows that the transition state structure has a more planar configuration than the TSA. The favorable electrostatic interactions between AZ28 and the transition state analogue overcome the unfavorable van der Waals interactions; thus, AZ28 shows higher binding affinity for the TSA than the germ line. However, the AZ28 is not flexible enough to accept the relatively planar transition state structure. Because the lower flexibility causes poorer antibody-hapten interaction energies, the activation free energy of the oxy-Cope rearrangement becomes larger in the mature antibody than the germ line. We show that the differences in flexibility between the germ line and the mature form and the differences in structure between TSA and the transition state are the origin of the negative correlation in AZ28-catalyzed oxy-Cope rearrangement. The mutation of residue 34 of the light chain, 34(L), affects the binding free energies through the interresidue interaction because it is the closest to the hapten among the six mutatable residues. However, it does not affect the negative correlation.

    DOI: 10.1021/ja020774a

    PubMed

    CiNii Article

  • Simulation studies of proton transfer in N2H7+ cluster by classical ab initio Monte Carlo and quantum wave packet dynamics

    T Asada, H Haraguchi, K Kitaura

    JOURNAL OF PHYSICAL CHEMISTRY A   105 ( 31 )   7423 - 7428   2001.08( ISSN:1089-5639

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    The quantum effects on the proton-transfer reaction in the N2H7+ cluster has been studied using the classical ab initio Monte Carlo method and a one-dimensional model for the quantum wave packet dynamics on the ab initio MP2/6-31 + G* potential energy surface. The optimized stable structure has C-3v symmetry, in which the proton is bound to one NH3 molecule in such a way that the proton feels bistable potential. In contrast, we found that the proton was located at the center of two NH3 molecules with D-3d symmetry due to the quantum effects of the proton kinetics. ne quantum simulations indicate that the reason the experimental spectra predict N2H7+ to have a symmetric D-3d Structure, contrary to the ab initio results, is that the quantum effects of the proton motion is completely neglected in the previous theoretical calculations. The vibrational frequency for the N-H stretching mode which corresponds to the proton transfer is estimated to be 706.7 cm(-1) by including proton quantum effects in contrast with 2100.1 cm(-1) obtained by the conventional ab initio MO method for the C-3v structure.

    DOI: 10.1021/jp004514w

  • Simulation studies of proton transfer in N2H7+ cluster by classical ab initio Monte Carlo and quantum wave packet dynamics

    T Asada, H Haraguchi, K Kitaura

    JOURNAL OF PHYSICAL CHEMISTRY A   105 ( 31 )   7423 - 7428   2001.08( ISSN:1089-5639

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    The quantum effects on the proton-transfer reaction in the N2H7+ cluster has been studied using the classical ab initio Monte Carlo method and a one-dimensional model for the quantum wave packet dynamics on the ab initio MP2/6-31 + G* potential energy surface. The optimized stable structure has C-3v symmetry, in which the proton is bound to one NH3 molecule in such a way that the proton feels bistable potential. In contrast, we found that the proton was located at the center of two NH3 molecules with D-3d symmetry due to the quantum effects of the proton kinetics. ne quantum simulations indicate that the reason the experimental spectra predict N2H7+ to have a symmetric D-3d Structure, contrary to the ab initio results, is that the quantum effects of the proton motion is completely neglected in the previous theoretical calculations. The vibrational frequency for the N-H stretching mode which corresponds to the proton transfer is estimated to be 706.7 cm(-1) by including proton quantum effects in contrast with 2100.1 cm(-1) obtained by the conventional ab initio MO method for the C-3v structure.

    DOI: 10.1021/jp004514w

  • Gaussian98を快適に利用する

    麻田俊雄

    総合情報センター年報 総合情報センター年報   6   49 - 54   2000.12

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  • Vibrational assignments of lithium alkyl carbonate and lithium alkoxide in the infrared spectra - An ab initio MO study

    S Matsuta, T Asada, K Kitaura

    JOURNAL OF THE ELECTROCHEMICAL SOCIETY   147 ( 5 )   1695 - 1702   2000.05( ISSN:0013-4651

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    We conducted nh initio molecular orbital calculations on stable monomer and dimer structures of lithium alkyl carbonates (methyl, ethyl, and propyl carbonate lithium) and lithium alkoxides (lithium methoxide, lithium ethoxide, lithium propoxide, and lithium butoxide). We confirmed that both lithium alkyl carbonates and lithium alkoxides adopted the dimer structure. The dimerization energies were approximately constant and independent of the alkyl group chain length. The dimerization energy was 214 kJ/mol for lithium alkyl carbonates and 266 kJ/mol for lithium alkoxides. Assignments of the vibration modes for each calculated frequency of lithium alkyl carbonates and lithium alkoxides were carried out. Vibrational frequency analysis recognized a dramatic vibrational frequency shift in the parts of the structure which changed significantly between the monomer and dimer structures (the lithium carbonate structure for lithium alkyl carbonates and the COLI structure for lithium alkoxides). Good agreement was achieved between calculated and experimental vibrational frequencies by shifting the frequency of the dimers, (C) 2000 The Electrochemical Society, SOD13-4651(99)09-059-X. All rights reserved.

    DOI: 10.1149/1.1393420

    CiNii Article

  • 高校生のための授業

    麻田俊雄

    総合情報センター年報   4   153 - 154   1998.12

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  • Theoretical prediction of intracluster reactions of B+(H2O)(2) and B+(H2O)(3): Hybrid procedure of ab initio MO calculations and Monte Carlo samplings

    H Watanabe, T Asada, S Iwata

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   70 ( 11 )   2619 - 2629   1997.11( ISSN:0009-2673 ( eISSN:1348-0634

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    A recently developed hybrid procedure of ab initio molecular orbital (MO) calculations and Monte Calro (MC) samplings is applied to investigate the intracluster reactions of B+(H2O)(n) (n = 2 and 3). In this procedure we do not assume the potential energy functions during MC samplings. At every step the ab initio MO method is directly used to evaluate the electronic energy. The procedure makes it possible to deal with the intra-cluster reaction involving any rearrangement of atoms such as isomerization and dissociation. The many-body effects on the energy are taken into account within the approximation used in the MO calculation. During the MC samplings at room temperature, the B+(H2O)(2) cluster undergoes a series of isomerization reactions, and eventually forms the most stable isomer, sp(2) type of trans HBOH+(H2O). For B+(H2O)(3), the reactions turn out to be more complicated, and a few times simulations suggest that there are several reaction products as well as intermediates in the reactions. The MO-MG procedure is proved to be a powerful tool to search for many isomers, reaction intermediates, and the products as well as the transition state structures between them although it is still very time-consuming.

    DOI: 10.1246/bcsj.70.2619

  • MELTING PHENOMENA OF CL-(H2O)2 CLUSTERS

    T ASADA, K NISHIMOTO, K KITAURA

    JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM   116   149 - 153   1994.07( ISSN:0166-1280

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    Melting phenomena were found in the calculated root-mean-square (r.m.s.) bond fluctuation (BF) using Monte Carlo simulation for the Cl-(H2O)2 cluster. From the results, the decrease region in the r.m.s. BF was also found as the temperature was increased just above the melting point, which has never been reported in argon clusters. The term ''irregular region'' for this region is used. These interesting phenomena have been partly interpreted using the partition functions of simple model potential functions for clusters with hydrogen bonding.

  • THEORETICAL-STUDY ON BINDING ENTHALPIES AND POPULATIONS OF ISOMERS OF CL-(H2O)N CLUSTERS AT ROOM-TEMPERATURE

    T ASADA, K NISHIMOTO, K KITAURA

    JOURNAL OF PHYSICAL CHEMISTRY   97 ( 29 )   7724 - 7729   1993.07( ISSN:0022-3654

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    The Monte Carlo simulations were performed for Cl-(H2O). (n = 1-8) at room temperature. The calculated enthalpy changes were in reasonable agreement with the experiments. The O-O radial distribution function of n = 2 clearly showed that the population of the ion-centered structure was larger than that of the pyramidal structure, though the former was energetically less stable than the later by 2 kcal/mol. The mole fractions of isomers were estimated by the partition function constructed using a simple theoretical model. The results suggest that the major isomer at room temperature is not necessarily the energetically most stable one, but the entropy-favored one.

    DOI: 10.1021/j100131a049

  • クラスターの構造とダイナミックス

    麻田俊雄,西本吉助

    化学同人 化学   47 ( 8 )   568 - 569   1992.12

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  • Structures and Dynamics of the Clusters

    47   1992

  • クラスターの構造とダイナミックス

    化学   47   1992

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Presentations

  • Computational Approach for Molecular Design with High Hole Mobilities using Random Forest Technique and Comnputer Simulation Method Invited

    Toshio Asada, Keijin Nakaguro, Takashi Yamaguchi, Tomohiro Oshiyama(Konica Minolta), Yuki Mitsuta

    2023.02 

  • 新規ジチエノベンゾチアゾール誘導体の半導体特性に対する置換基効果

    岡本温貴、岡田侑也、音野智哉、西田直之、佐藤寛泰、大垣拓也、太田英輔、松井康哲、林晃敏、永瀬隆、麻田俊雄、内藤裕義、池田浩

    第49回有機典型元素化学討論会  2022.12 

  • Fentanyl とその類似体の膜透過シミュレーション

    満田祐樹、麻田俊雄

    分子シミュレーション討論会  2022.12 

  • Computational investigation of the inhibition reaction on the free energy surface between SARS-CoV-2 Mpro and N3 complex Invited

    Toshio Asada

    2022.11 

  • Computational investigation of the inhibitor reaction on the free energy surface between SARS-CoV-2 Mpro and N3 complex Invited

    2022.10 

  • ジチエノベンゾチアゾールを基盤とした有機半導体の開発

    岡本温貴、 岡田侑也、音野智哉 、西田直之、佐藤寛泰、大垣拓也、太田英輔、松井康哲、林晃敏、永瀬隆、麻田俊雄 、内藤裕義、池田浩

    第32回基礎有機化学討論会  2022.09 

  • 遅延蛍光分子の発光特性の理論的解釈:二重井戸型ポテンシャル効果

    小関史朗、藤村勇一、河野裕彦、麻田俊雄

    第16回分子科学討論会  2022.09 

  • 機械学習を用いた新規ホール輸送剤の提案

    中畔 慶人、満田祐樹、小関史朗、麻田俊雄

    第16回分子科学討論会  2022.09 

  • 分子動力学シミュレーションによるL-Pro-Gly残基とD-Pro-Gly残基におけるタンパク質のフォールディング構造の比較

    勝 誉治、満田祐樹、麻田俊雄

    第16回分子科学討論会  2022.09 

  • 分子シミュレーションを用いた TEM-1 における脱アシル化反応の理論的研究

    小川美紀、小関史朗、満田祐樹、麻田俊雄

    第16回分子科学討論会  2022.09 

  • (Cyclopropylidenemethyl)benzeneにおける光化学反応の理論的解明:光励起によるカルベンの生成過程

    関戸竜也、麻田俊雄、小関史朗

    第16回分子科学討論会  2022.09 

  • 電荷移動度における多体効果の理論的解析

    田中 優衣、小関史朗、満田祐樹、麻田俊雄

    第16回分子科学討論会  2022.09 

  • 自由エネルギー反応経路ネットワークとマルコフ連鎖モデルを利用したタンパク質フォールディングのクラスタリング手法開発 Domestic conference

    満田祐樹、麻田俊雄

    日本化学会第102回春季年会(2022)  2022.03  日本化学会

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    Presentation type:Oral presentation (general)  

    Venue:オンライン  

  • ジチエノベンゾチアゾールを基盤とした有機半導体の開発:設計、合成、および電荷輸送特性 Domestic conference

    大垣拓也、岡本温貴、服部励太郎、中畔慶人、佐藤寛泰、松井康哲、太田英輔、麻田俊雄、内藤裕義、池田浩

    日本化学会第102回春季年会(2022)  2022.03 

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    Presentation type:Poster presentation  

  • Computational Approach for Molecular Design with High Hole Mobilities using Random Forest Technique and Comnputer Simulation Method Invited

    Toshio Asada

    APATCC-10  2022.02 

  • 有機半導体材料を志向した新規ジチエノベンゾチアゾール誘導体の合成と物性評価 Domestic conference

    岡本温貴、横山結太、服部励太郎、山口貴史、大垣拓也、太田英輔、松井康哲、麻田俊雄、内藤裕義、池田浩

    大阪府立大学研究推進機構21世紀科学研究センター2020年度分子エレクトロニックデバイス研究所(RIMED 第22回研究会)&機能性有機材料開発研究センター合同オンライン研究会  2021.11 

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  • 1-phenyl-methylenecyclopropane における光化学反応の理論的解明:励起状態の反応経路 Domestic conference

    関戸竜也、麻田俊雄、小関史朗

    大阪府立大学研究推進機構21世紀科学研究センター2020年度分子エレクトロニックデバイス研究所(RIMED 第22回研究会)&機能性有機材料開発研究センター合同オンライン研究会  2021.11 

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  • AIと分子シミュレーションによる高移動度電荷輸送材に適した分子設計システムの構築 Domestic conference

    中畔慶人、小関史朗、満田祐樹、麻田俊雄

    大阪府立大学研究推進機構21世紀科学研究センター2021年度分子エレクトロニックデバイス研究所(RIMED 第23回研究会)&機能性有機材料開発研究センター合同オンライン研究会  2021.11 

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  • 薬剤耐性タンパク質による抗生物質分解反応の理論的解析 Domestic conference

    大石怜、麻田俊雄、満田祐樹、小関史朗

    大阪府立大学研究推進機構21世紀科学研究センター2021年度分子エレクトロニックデバイス研究所(RIMED 第23回研究会)&機能性有機材料開発研究センター合同オンライン研究会  2021.11 

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  • 機械学習を用いた有機アモルファス半導体の正孔移動度予測 Domestic conference

    藤村颯、永瀬隆、小林隆史、麻田俊雄、内藤裕義

    第82回応用物理学会秋季学術講演会  2021.09 

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  • テトラチエノナフタレンの有機電界効果トランジスタにおけるアルキル鎖長効果

    久米田元紀、谷口公哉、山本惇司、末永 悠、麻田俊雄、松井康哲、服部励太郎、東中屋美帆、大垣拓也、太田英輔、内藤裕義、池田浩

    日本化学会第101回春期年会(2021)  2021.03 

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    Presentation type:Oral presentation (invited, special)  

  • 量子化学計算による有機アモルファス半導体の電子物性予測 -正孔輸送材料- Domestic conference

    藤村颯、永瀬隆、小林隆史、麻田俊雄、内藤裕義

    第68回応用物理学会春季学術講演会  2021.03 

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  • 熱活性化遅延蛍光(TADF)分子の幾何学構造に関する考察 Domestic conference

    福永直也、麻田 俊雄、小関史朗

    大阪府立大学研究推進機構21世紀科学研究センター2020年度分子エレクトロニックデバイス研究所(RIMED 第22回研究会)&機能性有機材料開発研究センター合同オンライン研究会  2020.12 

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  • 機械学習と分子シミュレーションを用いたホール輸送材の設計 Domestic conference

    山口貴史、麻田俊雄、小関史朗

    大阪府立大学研究推進機構21世紀科学研究センター2020年度分子エレクトロニックデバイス研究所(RIMED 第22回研究会)&機能性有機材料開発研究センター合同オンライン研究会  2020.12 

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  • http://fock.c.s.osakafu-u.ac.jp/~asada に記載

    麻田 俊雄

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Works

  • ナノサイエンス支援による協力研究

    2003

  • Joint Study Program of Institute for Moleculaar Science

    2003

  • Joint Research on Chemical Reaction in Antibody Molecule

    2001
    -
    2002

  • 抗体分子内化学反応に関する共同研究

    2001
    -
    2002

Collaborative research (seeds) keywords

  • 自由エネルギー反応経路最適化に関する技術

  • アモルファス相における電荷移動度の理論的予測と機械学習の応用

  • QM/MM法を用いた分子動力学シミュレーションによる構造、電子状態に関する理論的研究方法および実践方法

  • 機械学習による重要度評価

  • タンパク質の構造と機能についての理論的アプローチに関する技術

Outline of collaborative research (seeds)

  • 有機EL材料を含むホスト/ゲスト複合体に関する研究

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    独自のSuccessive Conduction法を用いてアモルファス層における電荷移動度を解析することが可能なので、これらを用いた計算科学的手法を適用することができるテーマとの共同研究が可能

  • タンパク質と基質およびタンパク質間の構造的機能的物性に関する研究

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    力場およびQM/MM法を用いて活性中心の自由エネルギー面上の反応機構を解析し、反応に関する自由エネルギー変化や基質との結合安定性などの解析法を生かす共同研究が可能

Grant-in-Aid for Scientific Research

  • 機械学習と量子化学計算による有機半導体創成と発光デバイス応用

    2021

  • 理論的アプローチによるアモルファス有機半導体の革新的設計手法の確立

    2021

  • 有機アモルファス半導体の電子物性予測への挑戦

    2021

  • 有機アモルファス半導体の電子物性予測への挑戦

    2020

  • 理論的アプローチによるアモルファス有機半導体の革新的設計手法の確立

    2020

  • 統合自由エネルギープロファイル解析に基づく革新的分子設計と反応制御法の開発

    2020

  • QM/MM法を用いた酵素反応の解析手法の共同研究

    2010

  • 有機EL燐光材料の理論的設計

    2009

  • 有機EL燐光材料の理論的設計

    2008

  • 有機EL燐光材料の理論的設計

    2008

  • 有機EL燐光材料の理論的設計

    2007

  • 有機EL燐光材料の理論的設計

    2007

  • 凝集反応系マルチスケールシミュレーションの研究開発 -大規模原子情報の疎視化・再構成技法・疎視的理論の開発-

    2006

  • 化学教育における計算機化学への取組みに関する研究

    2001

  • 化学教育における計算機科学への取組みに関する研究

    2001

  • クラスター内プロトン移動反応に及す溶媒効果の理論的研究

    2000

  • クラスター内プロトン移動反応に及す溶媒効果の理論的研究

    2000

  • 非経験的分子軌道法を用いた分子シミュレーションに最適な並列計算機環境の構築

    1999

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Charge of on-campus class subject

  • Physical Chemistry II

    2021    

  • Introduction to Programming

    2021    

  • Introduction to Life, Environment, and Advanced Sciences

    2021    

  • Quantum Chemistry

    2021    

  • Exercises in Physical Chemistry II

    2021    

  • Sciences in Community

    2021    

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Number of papers published by graduate students

  • 2022

    Number of undergraduate student / college student presentations:Number of graduate students presentations:0

Number of instructed thesis, researches

  • 2022

    Number of instructed the graduation thesis:Number of graduation thesis reviews:4

    [Number of instructed the Master's Program] (previous term):[Number of instructed the Master's Program] (letter term):0

    [Number of master's thesis reviews] (chief):[Number of master's thesis reviews] (vice-chief):7

    [Number of doctoral thesis reviews] (chief):[Number of doctoral thesis reviews] (vice-chief):0

Social Activities

  • 教員免許状更新講習 F1 授業で活かす科学トピックス(理科)

    2017.04 - 2018.03

  • 教員免許状更新講習 F1 授業で活かす科学トピックス(理科)

    2014.04 - 2015.03

  • 夢ナビライブ2012 in NAGOYA

    2012.04 - 2013.03

  • 夢ナビライブ2011

    2011.04 - 2012.03

Visiting Lectures ⇒ Link to the list of Visiting Lectures

  • 分子の世界 ミクロの小宇宙

    Category:Science (mathematics, physics, chemistry, biology, geology, biochemistry)

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    Audience:High school students, College students, Teachers, Researchers, General, Company, Civic organization

    Keyword:分子, 量子力学, 電子, 色 

    分子は原子核と電子からなる。これらは大変小さな粒子であり、われわれ身の回りにおこる常識が通用しないミクロの世界である。たとえば、電子は粒子の性質と波の性質を併せ持っている。さらに電子はとびとびのエネルギーしかとれず、これが物質が色をもつ原因にもなっている。本講座では、量子力学の基礎からはじめて、分子がどのようにして形成されているのか、また色がどうして出るのかについて解説する。